Radeon HD 4850 512MB vs Radeon HD 7770

Intro

The Radeon HD 4850 512MB features a core clock frequency of 625 MHz and a GDDR3 memory frequency of 993 MHz. It also features a 256-bit memory bus, and makes use of a 55 nm design. It features 800(160x5) SPUs, 40 TAUs, and 16 Raster Operation Units.

Compare all of that to the Radeon HD 7770, which comes with GPU core speed of 1000 MHz, and 1024 MB of GDDR5 memory set to run at 1125 MHz through a 128-bit bus. It also features 640 Stream Processors, 40 Texture Address Units, and 16 ROPs.

Price Comparison

Please note that the price comparisons are based on search keywords, and might not be the exact same card listed on this page. We have no control over the accuracy of their search results.

Radeon HD 4850 512MB Amazon.com Other US-based stores Amazon.co.uk Amazon.de Amazon.fr

Radeon HD 7770 Amazon.com Other US-based stores Amazon.co.uk Amazon.de Amazon.fr

Specifications

Model	Radeon HD 4850 512MB	Radeon HD 7770
Manufacturer	ATi	ATi
Year	Jun 25, 2008	February 2012
Code Name	RV770 PRO	Cape Verde XT
Fab Process	55 nm	28 nm
Bus	PCIe 2.0 x16	PCIe 3.0 x16
Memory	512 MB	1024 MB
Core Speed	625 MHz	1000 MHz
Shader Speed	N/A MHz	(N/A) MHz
Memory Speed	993 MHz	1125 MHz
Unified Shaders	800(160x5)	640
Texture Mapping Units	40	40
Render Output Units	16	16
Bus Type	GDDR3	GDDR5
Bus Width	256-bit	128-bit
DirectX Version	DirectX 10.1	DirectX 11.1
OpenGL Version	OpenGL 3.0	OpenGL 4.2
Power (Max TDP)	110 watts	80 watts
Shader Model	4.1	5.0
Bandwidth	63552 MB/sec	72000 MB/sec
Texel Rate	25000 Mtexels/sec	40000 Mtexels/sec
Pixel Rate	10000 Mpixels/sec	16000 Mpixels/sec

Memory Bandwidth: Memory bandwidth is the max amount of information (in units of megabytes per second) that can be transferred over the external memory interface in a second. It is worked out by multiplying the card's bus width by the speed of its memory. In the case of DDR type RAM, the result should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The higher the card's memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are applied in one second. This figure is calculated by multiplying the total amount of texture units by the core speed of the chip. The better the texel rate, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in a second.

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip can possibly record to its local memory per second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on quite a few other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the maximum fill rate.